package net.esj.basic.utils;

import java.net.InetAddress;
import java.net.UnknownHostException;

public final class ServerUtils {

	public static String getServerIp() {
		try {
			InetAddress addr = InetAddress.getLocalHost();
			return addr.getHostAddress().toString();
		} catch (UnknownHostException e) {
			e.printStackTrace();
			return "";
		}
	}
	
	//将127.0.0.1形式的IP地址转换成十进制整数，这里没有进行任何错误处理    
    public static long IpToLong(String strIp){    
        long[] ip = new long[4];    
        //先找到IP地址字符串中.的位置    
        int position1 = strIp.indexOf(".");    
        int position2 = strIp.indexOf(".", position1 + 1);    
        int position3 = strIp.indexOf(".", position2 + 1);    
        //将每个.之间的字符串转换成整型    
        ip[0] = Long.parseLong(strIp.substring(0, position1));    
        ip[1] = Long.parseLong(strIp.substring(position1+1, position2));    
        ip[2] = Long.parseLong(strIp.substring(position2+1, position3));    
        ip[3] = Long.parseLong(strIp.substring(position3+1));    
        return (ip[0] << 24) + (ip[1] << 16) + (ip[2] << 8) + ip[3];    
    }
        
    //将十进制整数形式转换成127.0.0.1形式的ip地址    
    public static String LongToIp(long longIp){    
        StringBuffer sb = new StringBuffer("");    
        //直接右移24位    
        sb.append(String.valueOf((longIp >>> 24)));    
        sb.append(".");    
        //将高8位置0，然后右移16位    
        sb.append(String.valueOf((longIp & 0x00FFFFFF) >>> 16));    
        sb.append(".");    
        //将高16位置0，然后右移8位    
        sb.append(String.valueOf((longIp & 0x0000FFFF) >>> 8));    
        sb.append(".");    
        //将高24位置0    
        sb.append(String.valueOf((longIp & 0x000000FF)));    
        return sb.toString();    
    }  
}
